The report, commissioned by the US Food and Drug Administration (FDA) from the independent Institute of Medicine (IOM) and National Research Council of the National Academies, is designed to boost the FDA's ability to evaluate the safety of dietary supplements, under heightened scrutiny in recent months owing particularly to reports that the herbal ephedra may have caused death.
Supplements in the US are regulated under the Dietary Supplement Health and Education Act (DSHEA), established in 1994. It gives supplements a legal status similar to foods, and considers them to be safe unless proved otherwise by FDA.
But the IOM report argues that this assumption of safety before reaching the market means FDA does not need to wait for evidence of harm to humans to take action; rather the agency must show that a product poses an unreasonable risk to users, which could be elucidated from data from animal studies and in vitro tests alone.
Furthermore, historical use is not always enough by itself to prove the safety of a supplement, even if it has been consumed for centuries, and changes in how an ingredient is formulated or processed raise the potential for new adverse effects, said the committee.
"In some cases, data on an ingredient's safety in humans are scant or nonexistent. Our report describes how other types of data - such as the results of tests in animals, or information on similar substances - can be used in a science-based approach to determine whether a supplement poses a significant risk to human health," said Barbara Schneeman, chair of the committee that wrote the report and professor of nutrition, food science, and internal medicine, University of California, Davis.
The report comes at a time when the US industry, facing growing pressure from consumer media, has begun to urge FDA to 'use the powers' it has under DSHEA to regulate supplements, in order to reduce criticism that the sector is unregulated and dangerous to consumers.
But it is facing greater FDA action in the wake of the ephedra issue and a number of government bills calling for tighter regulation, to include mandatory adverse reporting (also supported by the IOM report).
However the IOM findings could have an impact on other markets too. The report includes reviews of six ingredients as prototypes for the system, which categorises different kinds of data that can be used to assess safety and guidelines for determining the significance of the evidence available on a particular substance.
For example, the reviews found that melatonin and chromium picolinate appear to be safe, but glucosamine, used to support joint health, may pose risk to people with insulin resistance, while saw palmetto could be unsafe for women likely to become pregnant.
The report also calls for supplement makers, the public, and others to increase their reporting of health problems related to supplement use to help the FDA 'protect consumers'.
Annual sales of dietary supplements in the United States are approaching $16 billion, with an average 1,000 new products developed each year. But lack of reporting significantly hampers the agency's ability to actively monitor supplement safety, the report says. The Office of the Inspector General estimates that FDA receives reports on less than half of 1 per cent of all adverse events associated with supplements.
To further boost reporting, labels on supplements should include a toll-free number for consumers and health professionals to call in health problems or concerns related to the product, the committee said.
Industry has not yet had time to digest the report but it is likely to be critical of the lack of industry representatives on the committee.